Method, system, and program for transferring data from an application engine

ABSTRACT

Provided is a method, system, and program for enabling access to resource objects in an application engine. A request is received from a calling entity for resource objects of a specified type in the application engine. A request to the application engine is generated for information on available resource objects of the specified type. In response to receiving the information from the application engine, a collection object is generated including one metadata element for each resource object of the specified type in the application engine. The generated collection object is returned to the calling entity.

RELATED APPLICATIONS

This application is related to the following copending and commonlyassigned patent applications, which are incorporated herein by referencein their entirety:

-   -   “Method, System, and Program for Generating a Workflow”, having        U.S. Pat. No. 7,100,147, which was filed on Jun. 28, 2001 and        issued Aug. 29, 2006;    -   “Method, System, and Program for Using Objects In Data Stores        During Execution of a Workflow”, having U.S. Pat. No. 7,043,714,        filed on Jun. 28, 2001 and issued May 9, 2006;    -   “Method, System, and Program for Executing a Workflow”, having        U.S. Pat. No. 7,069,536, filed on Jun. 28, 2001 and issued on        Jun. 27, 2006; and    -   “Method, System, And Program For Enabling Access to a Plurality        of Services”, having U.S. Pat. No. 7,228,547, filed on Jul. 30,        2001 and issued on Jun. 5, 2007.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method, system, and program fortransferring data from an application engine.

2. Description of the Related Art

A workflow program allows businesses and other organizations to definetheir business operations as a computer model known as a workflow. Aworkflow defines a series of processes to be performed by users at aclient computer. The user activities at the client computers may involveupdating an electronic form, reviewing information, etc. After one userin the workflow performs a specified action, the work item or otherinformation is then routed to one or more further nodes where furtheraction may be taken. For instance, an on-line purchase of a product mayinvolve numerous steps, such as receiving the customer order, routingthe customer order to the credit department to process the bill and thenrouting the order to the shipment department to prepare the shipment.Once the shipment is prepared, the product may be shipped andinformation on the purchase is then transferred to the customer servicedepartment to take any further action. Each of these processes may bedefined as nodes in a workflow. A workflow program would then route thecustomer order to the business agents designated to handle the job. Forinstance, the initial order would be received by the order departmentand then routed to a person in shipping and billing. Once the bill andpackage are prepared, a further invoice may be forwarded to shipping.After shipping sends the package, the shipping agent may then enterinformation into the invoice and forward the electronic invoice tocustomer service for any follow up action.

A workflow is designed using workflow software, such as theInternational Business Machines (IBM) MQSeries Workflow softwareproduct. Often application programs that interface with a workflowengine require information on workflows operating at the workflowengine. The process of transferring information from the workflow engineto an application over a network can take a considerable amount of timeand burden network resources given the large size of data used todescribe workflows available at a workflow engine.

For these reasons, there is a need in the art to provide improvedtechniques for providing information on workflow and other servicesavailable in a network environment to application programs.

SUMMARY OF THE PREFERRED EMBODIMENTS

Provided is a method, system, and program for enabling access toresource objects in an application engine. A request is received from acalling entity for resource objects of a specified type in theapplication engine. A request to the application engine is generated forinformation on available resource objects of the specified type. Inresponse to receiving the information from the application engine, acollection object is generated including one metadata element for eachresource object of the specified type in the application engine. Thegenerated collection object is returned to the calling entity.

In further implementations, the application engine is one of a pluralityof service engines enabling access to service resources. The request forthe resource objects from the calling entity comprises a method that isa member of a service class implementation of the application engine,wherein each service engine provides one service class implementation ofmethods and objects from a same abstract service class.

Still further, the collection object is generated using methods from acollection object class. A retrieve method is received in the collectionobject class from the calling entity requesting the resource objectrepresented by one selected metadata element in the collection object.An additional request to the application engine is generated for theresource object requested in the retrieve method. The requested resourceobject is received from the application engine and the requestedresource object is returned to the calling entity invoking the retrievemethod.

The described implementations provide a technique to allow anapplication or user to receive information on resources available at anapplication engine and retrieve the resource objects for certain of theresources identified in the information. With the describedimplementations, information on resources available in the applicationengine and the resources themselves are provided as needed.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the drawings in which like reference numbers representcorresponding parts throughout:

FIG. 1 illustrates a workflow computing environment in which aspects ofthe invention are implemented;

FIG. 2 illustrates logic performed by a workflow server to execute aworkflow in accordance with implementations of the invention.

FIG. 3 illustrates an architecture of object oriented classes forimplementing a workflow in accordance with implementations of theinvention; and

FIGS. 4 and 5 illustrate logic to utilize the methods and objects fromthe object oriented class architecture of FIG. 3 to execute a workflowin accordance with implementations of the invention;

FIG. 6 illustrates an architecture of object oriented classes forimplementing workflow services for heterogeneous services in accordancewith implementations of the invention;

FIG. 7 illustrates an implementation an environment for enabling accessto heterogeneous services in accordance with implementations of theinvention;

FIG. 8 illustrates an example of a service object maintaininginformation on services in accordance with implementations of theinvention;

FIG. 9 illustrates logic to construct a service in accordance withimplementations of the invention; and

FIG. 10 illustrates logic to construct a connection object in accordancewith implementations of the invention;

FIG. 11 illustrates logic to obtain information on a named service inaccordance with implementations of the invention;

FIG. 12 illustrates an example of a collection object including metadatain accordance with implementations of the invention;

FIG. 13 illustrates logic to provide information on resources for anengine in accordance with implementations of the invention; and

FIG. 14 illustrates logic to access resource objects for which metadatainformation is included in the collection object.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following description, reference is made to the accompanyingdrawings which form a part hereof and which illustrate severalembodiments of the present invention. It is understood that otherembodiments may be utilized and structural and operational changes maybe made without departing from the scope of the present invention.

FIG. 1 illustrates a workflow environment implementation in which theinvention is realized. A workflow engine 2 includes a runtime database 4and a workflow server 6, such as the IBM MQSeries Workflow server. Theworkflow server 6 is capable of transforming a workflow model coded in aworkflow definition language (WDL) file 10, such as FDL, into a processtemplate 8 implemented in the runtime database 4. The runtime database 4stores database tables that implement the data structures that providethe status and setup information needed for workflow process execution.Whenever the state of a process activity changes, such information isrecorded in the runtime database 4. The runtime database 4 may beimplemented using any database program known in the art, such as IBMDB2.** **MqSeries, IBM, and DB2 are registered trademarks ofInternational Business Machines Corp., Java is a trademark of SunMicrosystems, Inc.

The workflow server 6 coordinates and manages the execution of processesfor a defined process template 8. The workflow server 6 executes anyprograms associated with a process defined for the workflow, interpretsthe process definitions, creates process instances and manages theirexecution, manages processes and states, logs events, communicates withusers as part of the workflow, etc. The workflow server 6 may include adatabase client program (not shown) to access and update records relatedto the workflow being processed maintained in the runtime database 4.The workflow server 6 processing may be distributed across multiplecomputers to achieve workload balancing.

The workflow clients 12 a, b . . . n represent the client computers thatexecute workflow application program interfaces (APIs) to performworkflow related actions and activities and return messages to theworkflow server 6. The workflow clients 12 a, b . . . n thus compriseinstances of the workflow code on the client computers that allow usersto interface with the executing workflow and the workflow server 6. Theworkflow server 6 would execute activity programs as part of executingthe workflow and transmit messages and data to the workflow client 12 torequest user action to proceed with the workflow. The actions associatedwith the nodes and executed by the workflow server 6 may comprise Javaservlets. The workflow client 12 may comprise a Web browser capable ofexecuting Java scripts transferred from the Java servlet executing onthe workflow server 6. Further, details on implementations andinteractions of the workflow server 6 and client 12 are described in theIBM publication “IBM MQSeries Workflow: Concepts and Architecture,Version 3.3”, IBM document no. GH12-6285-03 (March, 2001), whichpublication is incorporated herein by reference in its entirety.

A workflow builder 20 comprises a system including a buildtime program22 that implements a plurality of graphical user interface (GUI) panelsin which a user may define the components of a workflow model 24. Aworkflow translator 26 converts the workflow model 24, with the definedworkflow components, into a workflow definition language (WDL) file 10that implements the workflow model 24. The workflow definition language(WDL) may comprise the FlowMark Definition Language (FDL), WorkflowProcess Definition Language (WPDL) or any other workflow definitionlanguage known in the art that is used to define workflows. The workflowtranslator 24 would transfer the WDL file 10 to the workflow server 6 totransform into a process template 8 in the runtime database 4 in amanner known in the art. Further details of using the buildtime program22 to build workflows are described in the cop ending and commonlyassigned patent application “Method, System, and Program for Generatinga Workflow”, having Ser. No, 09/894074 which application wasincorporated herein by reference above.

The workflow engine 2, and each of the program components therein, suchas the runtime database 4 and workflow server 6, may be implemented inone or more computing machines. The workflow clients 12 which providethe workflow interface to users may be implemented on one or more clientmachines. The workflow builder 20, including the buildtime program 22and workflow translator 26 programs, may be implemented on one or morecomputing machines. Any portion of the workflow engine 2, workflowbuilder 20, and/or workflow client 12, and program components therein,may be implemented on the same computing machines or separate machines.The computing machines used to implement the workflow engine 2, workflowclients 12, and workflow builder 20 may comprise any computing deviceknown in the art, such as a server, workstation, mainframe, personalcomputer, laptop computer, hand held computer, telephony device, etc.

One use of a workflow is to generate a final product, which may comprisethe result of the effort of a single business unit or the cumulativeefforts of multiple users and units within an organization. To producethe final product, a workflow packet comprised of one or more documentswould transfer through various user work stations in the company definedas nodes in the workflow to require the user associated with such nodeto handle and process and forward to another user to handle. A documentis comprised of a multimedia item that has digital content.

For instance, an insurance company may have to process numerousdocuments related to an insurance claim, such as photographs,appraisals, expert reports, etc. Employees may spend a substantialamount of time sorting through documents and associating the documentswith particular claims. In the workflow model, all the documents relatedto a single claim would be part of a work packet that may move throughvarious user stations to review and process. The workflow would comprisethe flow of work and actions that are performed on the documents orworkflow packet by multiple users in the system.

The workflow defines the sequence and boundaries of how the work isperformed with respect to the documents in the workflow packet, and anyrestrictions on the order in which documents in the workflow packet mustbe processed. For instance, before the claim can proceed to a furtherstep, a claims adjuster might be required to ensure that certaindocuments are included in the workflow packet for the claim before theworkflow packet can proceed to further nodes in the workflow, e.g.,determining the amount of compensation.

In workflow terminology, a worklist is a queue of work items. Each workitem comprises a unit of work for a node in the workflow that isperformed by the users associated with that node. Each work item may beassociated with one work packet, which comprises documents or objectsthat are processed during the work defined for that work item. When auser at one node accesses the work item to perform the work definedtherein, that work item is locked, thereby preventing others at thatnode from accessing the work item.

A worklist, which is a queue of work for the users of the organizationto perform with respect to the workflow packet. The work items withinthe worklist can be handled by any of the employees/users assigned tothe worklist. An action list defines the actions that a user can performon the work packet objects associated with the work item, such asselections or data that may be entered in the work packet. For example,an adjuster in the claim process workflow can select an option tocontinue consideration of the claim if it appears valid or select anoption to reject the claim. The workflow further consists of the pathsdefined as the connections between nodes which indicate the order ofexecution of nodes in the workflow.

An action list may be associated with a workflow that provides a listthe actions that can be invoked at the nodes in the defined workflow.The actions may comprise programs that are executed at a particularnode. In certain implementations, the actions comprise Java methods thatthe workflow server 6 executes when control proceeds to the node withwhich the method is associated. Action in the list would be associatedwith particular nodes. An access list defines a mapping of users thatcan be assigned to nodes to perform the action associated with suchnode. An notification feature causes a message to be sent to a specifieduser if the user associated with a node has not performed the actiondefined for the node within a specified time frame.

One or more actions and a user with are associated with the work nodesin the workflow. The work nodes defined for the workflow may comprise adecision point node, collection point node, document node, and assignvalue node. A decision point node causes the workflow to proceed along abranch of execution based on selection by the user or some other actiontaken by an external application called at a previous work node. Forinstance, the path taken to the next node in the workflow may vary ifthe claim adjuster selects to reject the claim as opposed to approvingthe claim. A collection point node is a work node where certaindocumentation is gathered and added to the work packet. The collectionnode holds and manages work packages that cannot be processed completelyuntil additional information is received. A document node represents adocument in the workflow.

In certain implementations, the workflow model 24 defined using thebuildtime program 22 is document centric in that the actions performedat the node concern the processing of work packages that may compriseany content or object that is processed and routed through the workflow.FIG. 2 illustrates the logic performed by the workflow server 6 toexecute a workflow. When a user invokes a workflow stored in the runtimedatabase 4, the workflow server 6 accesses (at block 100) the start nodeof the invoked workflow by interacting with the runtime database 4 in amanner known in the art. From the properties defined for that node, theworkflow server 6 determines (at block 102) the actions and userassociated with the node. The workflow server 6 further processes (atblock 104) the access list defined for the workflow to determine thework item for the accessed node. If (at block 106) the determined workitem currently accessed in the workflow is locked by another user atthat node, then the workflow server 6 waits (at block 108) for the lockon the work item(s) to be released. If the work item is not locked orafter the lock is released, control proceeds to block 110 where theworkflow server 6 places a lock on the determined work item. Theworkflow server 6 then executes (at block 112) the action associatedwith the node and communicates data to the workflow client 12 of thedetermined user requesting user action.

If (at block 114) notification is enabled for the current node and thedeadline has passed (at block 116) without receiving a response from theuser, then the workflow server 6 notifies the user specified with theenable notification that the deadline has passed. Upon receiving (atblock 118) a response from the user, which may comprise enteringinformation, modifying a work item, adding a work item to the workpackage, selecting an option, etc., the workflow server 6 unlocks (atblock 120) the work item(s) previously locked for the user. If (at block122) the current node is the stop node, then control ends; otherwise, ifthere are further nodes to process in the workflow, then the workflowserver 6 determines (at block 124) from the path from the current nodethe next node in the workflow and accesses (at block 126) the next node.Control then proceeds back to block 326 to process the next node.

The workflow logic of FIG. 2 provides a document centric workflow inthat the state of processing work items associated with the nodecontrols the workflow because control cannot proceed to other subsequentnodes that process the locked work item until the node holding the lockcompletes execution and releases the lock on the work item. Thus, accessto work items controls the flow through the workflow.

With the described implementations, the workflow builder 20 generates aWDL file 10 that may be compatible with workflow engines from differentvendors because different vendors may design their workflow engines tobe compatible with the WDL format of the WDL file 10. This allows theworkflow model defined in the WDL file 10 to be transportable acrossdifferent vendor workflow engine platforms.

Object Oriented Workflow Architecture

FIG. 3 illustrates an architecture of object oriented classes and theirinterrelationship that are used to implement a workflow of nodes. Asindicated in the legend 400, a rectangle indicates a class; a lineconnecting classes indicates an association of the connected classes; aline connecting classes terminating in a filled circle indicates thatthere may be one or more instances of the class at the end with thecircle for each instance of the class at the other end of the line; anda line terminating at a diamond indicates that the class at the diamondend is an aggregate, such that the aggregate object is made up of one ormore instances of the class at the other end of the line. FIG. 3illustrates the relationship of the classes.

The WorkFlowService class 402 is the starting point for a user wantingto access a workflow. The WorkFlowService class 402 includes methodsthat allow users to access already defined workflow templates andexecuting workflows. The WorkFlowService class 402 is associated withthe WorkFlowTemplate 404, WorkFlow 406, and WorkFlowList 408 classes.The WorkFlowTemplate class 404 provides methods that allow the user tomanipulate workflow process template objects, e.g., process template 8(FIG. 1), which comprise a defined workflow that is stored in theworkflow engine 2. The WorkFlow class 406 provides methods that allowthe user to access information and control an executing workflow. TheWorkList class 408 includes methods that allow the user to access anexecuting work list object comprised of work items and information onthe current state of the executing work list, i.e., information on workitems being processed. The methods in the WorkFlowService class 402 areused to retrieve information on particular workflows, workflowtemplates, and workflow lists associated with a particular workflowservice. The methods from the other classes, such as theWorkFlowTemplate 404, WorkFlow 406, and WorkFlowList 408 classes, canthen be used to obtain specific information and control over thoseworkflow templates, workflows, and workflow lists identified by theWorkFlowService class 402 methods.

The WorkFlowTemplate class 404 provides information on a workflowtemplate. A workflow object from the WorkFlow class 406 represents anexecuting workflow. The WorkFlowContainer class 410 includes methods toinstantiate a container object that includes information on onecontainer used to transfer data between nodes. Users at nodes may accessdata in the container and update the container with additional data. Thedata in the container may be used by the action being executed at anode. The WorkFlow class 406 is associated with the WorkFlowNotificationclass 412, which is used to provide notifications, such as notificationsif a user does not perform an action at a node within a predefined timeperiod. There may be many notifications provided for one workflow. TheWorkFlow class 406 is further associated with the WorkFlowItem class414, such that one executing workflow may be associated with one or morework items indicating a unit of work to perform for a node within theworkflow. The WorkFlowItem class 414 is associated with theWorkFlowContainer class 410, such that one container may be used at awork item to provide data to the user executing the unit of work definedby the work item. The relationship between the WorkFlow class 406 andthe WorkFlowItem class 414 indicates that there may be many work itemobjects associated with one executing workflow. The class architectureof FIG. 10 further illustrates that a workflow list of the WorkFlowListclass 408 is an aggregate of the workflow from the WorkFlow 414 Itemclass and workflow notifications from the WorkFlowNotification 412class.

The above object oriented architecture of FIG. 10 defines how thedifferent classes interrelate in order to implement a workflow. Each ofthe above interrelated classes 402, 404, 406, 408, 410, 412, and 414provides interfaces/methods that may be used within a workflow computerprogram to implement the workflow and actions performed at a node. Theworkflow program would be executed by the workflow server 6 (FIG. 1) inthe workflow engine 2.

Following are examples of some methods of the WorkFlowService class 402,including:

-   -   WorkFlowService( ): constructs a new workflow service, which        provides access to different workflow services in the workflow        engine 2 (FIG. 1). Each workflow service is associated with        workflow templates, executing workflows, and workflow lists of        work items for a workflow.    -   connect: provides a user name, authentication, and connection        string to use to authenticate a user to provide access to a        requested workflow service, which allows access to workflow        templates, work lists, etc.    -   connection: handle returned to a user to allow access to a        particular workflow service.    -   setDatastore: a reference to a data store including documents        and objects used by the work items in the workflows associated        with the workflow service. Thus, different workflows for a        workflow service may process documents within workflow packages        from the same data store.    -   listWorkFlows: returns a list of all workflow objects of the        WorkFlow class 406.    -   listWorkLists: returns a list of all work list objects of the        WorkFlowList class 408.    -   listWorkFlowTemplates: returns a list of all template objects of        the WorkFlowTemplate class 404.

Following are examples of some methods of the WorkFlowService class 402,including:

-   -   WorkFlowTemplate( ): constructs a workflow template object        including a defined workflow. This workflow template may be        created using the GUI panels and buildtime program described        above.    -   name: returns name of a workflow template.    -   description: returns a description of the work performed by a        workflow template.    -   modifiedTime: time the workflow template was last modified.

Following are examples of some methods of the WorkFlow class 406,including:

-   -   WorkFlow( ): constructs a workflow object representing a        workflow comprised of nodes and work items for a specified        workflow. The workflow may also be provided a container that is        used to allow users of different work items to commnunicate        and/or a work packet comprised of one or more documents or        objects to be processed as part of the workflow.    -   get/setName: returns or sets the name for a workflow.    -   workFlowTemplateName: returns the name of the workflow template        associated with the workflow.    -   notificationTime: returns the time of the last notification        generated for the workflow in response to a user not performing        an action for one accessed node within a specified time period.    -   modifiedTime: Returns the last time the workflow was modified.    -   stateChangeTime: returns the last time a state change occurred        with the workflow:    -   startTime: returns the time the workflow was started.    -   endTime: returns the time the workflow ended.    -   state: returns a state of the workflow, such as ready, running,        finished, terminated, suspended, terminating, suspending,        deleted, etc.    -   inContainer: returns the input container associated with the        workflow.    -   start: starts a workflow with a container if the state is ready.    -   terminate: terminates the workflow if the state is running,        suspended, or suspending.    -   suspend: suspends the workflow if the state is running.    -   resume: resumes a suspended workflow if the state is suspended        and suspending.    -   add: adds a workflow to the system that is associated with one        specified workflow template.

Following are examples of methods of the WorkFlowContainer class 410,which instantiates a container object used with a workflow to transportinformation among the nodes.

-   -   WorkFlowContainer( ): constructs a container object for a        container used within a particular workflow.    -   get/setPriority: get/sets the priority for an item in the        container.    -   get/setActivityNode: get/sets the current node being processed,        may also get/set information on the current activity node.    -   get/setWorkPacketID: get/sets an identifier of a work packet        being routed through the system.    -   get/setActionPerformed: get/sets information on an action being        performed.    -   get/setUserVariable: get/sets a variable maintained in the        container, that may have predefined values. The priority is        maintained for a user variable in the container.    -   retrieve: retrieves and refreshes the container.    -   update: updates the container data.

Following are examples of some methods of the WorkList class 408, wherea work list object is a representation of a work list in the system. Asdiscussed, a work list object comprises a collection of work items andnotifications for an executing workflow.

-   -   WorkList( ): constructs a work list object for a specified work        list. A work list consists of work items.    -   get/set ACLName: get/sets the action control list (ACL) name for        the work list including the actions that may be performed as        part of units of work for the work list.    -   listWorkltems: lists the work items on the work list.    -   listWorkItemsByTemplate: returns the work items for the work        list by the specified workflow template name.    -   listWorkItemsByNode: returns a list of the work items assigned        to each node in the work flow.    -   listProcessNotifications: lists notifications generated during        workflow that are associated with the workflow process. For        instance, the notification enabled through the GUI in FIG. 3        provides a general notification for the workflow. In certain        implementations, a notification process is activated and        performed as a background process to generate notifications.    -   listActivityNotifications: lists notifications generated during        workflow that are associated with a particular activity, such as        a user not performing an activity within a specified time. For        instance, the notification enabled through the GUI of FIGS. 4        and 5 enables notifications for activities at particular nodes.    -   add/update/delete/retrieve: separate commands that allow user to        add, update, delete, and retrieve a work list.

Additional commands may be provided to access the information in thework list, such as filter commands to provide filters for accessinginformation from the work list, thresholds of the number of items thatcan be in the work list, etc.

Following are examples of some methods of the WorkFlowItem class 414,where a work item object represents a unit of work performed in theworkflow. The following methods are used to create and modify workitems, and obtain information thereon.

-   -   WorkFlowItem( ): constructs a work item for a specified        workflow, node, and owner.    -   name: returns the name of the node to which the work item is        assigned.    -   state: returns a state of the work item, such as not set, ready,        running, finished, terminated, suspended, disabled, checked out,        in error, executed, etc. A work item is checked out when a user        has accessed the work item to perform the actions defined for        the work item.    -   workFlowName: returns the name of the workflow including the        work item.    -   workFlowTemplateName: returns the name of the workflow template        including the work item.    -   priority owner, notificationTime. startTime, creationTime        modifiedTime: methods that return information on the priority,        owner, time of last notification, time of creation and time of        last modification for a work item, respectively.    -   retrieve, start, finish: methods used to retrieve, begin        executing, and complete a work item, respectively.    -   checkIn, checkOut: checkOut locks a work item to prevent other        users at a node from accessing the work item and changes the        state of the work item to checked out. Upon check out, the        container associated with the work item is accessed from the        previous node using the inContainer method. The checkIn method        receives the completed work item from the user, releases the        lock, and provides the container to route to the next node.    -   inContainer: method that obtains container from previous node        for use with work item checked out at current node being        processed.    -   outContainer: method generates an out container to include        contents of container user accessed at work item, including any        changes made by the user to the data in the container. A handle        of the out container is generated and provided with checkOut        method called for the next node to provide that container to the        user of the next node in the workflow.

Following are examples of some methods of the WorkFlowNotification class412, where a notification object represents a generated notification.The following methods are used to create and modify notifications, andobtain information thereon.

-   -   WorkFlowNotification( ): constructs a notification object having        a specified notification name, notification type, and owner name        for a specified workflow service and workflow. The notification        type indicates how the owner is notified. state: returns a state        of the notification, such as not set, ready, running, finished,        terminated, suspended, disabled, etc.    -   priority, owner, notificationTime, startTime, creationTime,        modifiedTime, receivedTime: these methods return the priority of        the notification, owner of the notification, time that must        elapse before the notification is generated, time the        notification started, time the notification was crated, time of        last notification to the notification, time the notification was        received, respectively. The notification would be started and        executed as a background process.    -   receiveReason: returns a received reason for the notification.    -   retrieve, cancel: methods that retrieve and cancel a        notification, respectively.    -   transfer: transfers a notification to a specified user. In this        way, a notification can be transferred from the current owner to        some other user.

The above described methods and classes would be included in a workflowprogram executed by the workflow server 6 (FIG. 1) to execute theworkflow. The methods described above would be used to access and modifythe workflow related objects, such as the workflow, work items,notifications, containers, etc. when running the workflow. The abovedescribed methods may also be used in other programs that can obtaininformation and status on a workflow.

FIGS. 4-5 illustrate an example of program logic in a workflow programexecuted by the workflow server 6 (FIG. 1) utilizing the above discussedmethods to implement a workflow. With respect to FIG. 11, control beginsat block 450 where the program calls the constructor methods,WorkFlowService( ) to construct a workflow service object. The workflowprogram would then call (at block 452) the WorkFlowService list methods,such as listWorkFlows, listWorkLists, listWorkFlowTemplates, to obtaininformation on the workflows, workflow templates, and work lists for aworkflow service. This information may then be presented to a user forselection. Various other methods in the classes may be called to accessinformation on the workflow to present to the user when making adecision on which workflow to execute.

At block 454, user selection of a workflow to process is received. Theworkflow program then calls (at block 456) the WorkFlow start method tostart the workflow. The workflow program then calls (at block 458) thelistWorkltemsByNode method to obtain all the work items for the startedworkflow, and the nodes to which the one or more items are associated.The workflow program then performs a loop at blocks 460 through 490 foreach node i in the workflow, as determined from the list of work itemsby node. For each node i, the workflow program performs a loop at block462 to 488 for each work item j associated with node i. If (at block464) there is a notification for the work item and the user that is theowner of the item, as determined from the methods, then the workflowprogram retrieves (at block 466) retrieves the notification and thenstarts a monitor to determine if the time period for the notificationhas elapsed without the work item completing. From block 464 or 466, theworkflow program calls (at block 468) the checkOut method to lock thework item j. The inContainer method is called (at block 470) to accessany container associated with the work item j. Once the work item j islocked, the workflow program then executes (at block 474) the actionsassociated with the work item j.

Control then proceeds to block 476 in FIG. 5, where the workflow programcalls container get and set methods to access or modify the data andvariables in the container accessed for the work item j in response toexecuting actions assigned to that work item j. For instance, as part ofperforming actions for a work item, the user of the work item may readand write data to the container. The workflow program receives (at block482) indication from a user that the actions associated with the workitem have completed. The workflow program further calls (at block 486)the checkIn method to release the lock on the work item j and theoutContainer method to generate a new container including any updates toprovide to the user at the next node in the workflow. The handle to thenew container would be used in the next called checkOut method toprovide the container to the user at the next node of the workflow. Ifthere are further work items for the node i, then control proceeds (atblock 488) back to block 452 to retrieve the next work item. Aftercompleting all the work items for node i, control proceeds (at block490) back to block 460 to process the next node in the work list.

The above described logic utilized workflow related classes and themethods therein to implement a workflow and obtain information thereon.The workflow server 6, or some other component in the workflow engine 2(FIG. 1), would then translate the workflow objects and methods intoapplication specific commands, such as Structured Query Language (SQL)commands to manipulate the data in the runtime database 4 and processtemplate 8 to obtain information on the workflow and implement workflowoperations.

Enabling Access to Heterogeneous Services

The above described architecture described how programmers in aclient/server worfklow environment can write application programs toperform worfklow related operations using an object oriented classarchitecture. Further implementations provide methodologies for allowinga client application program to utilize heterogeneous services, e.g., aworkflow program, search engines, a data repository and program foraccessing a data repository (such as the IBM Content Server*) etc., fromdifferent vendors. A service is a set of functionality or program thatmay be accessed and executed, such as a workflow program.

FIG. 6 illustrates an architecture of a client/service server frameworkto provide access to different types of service programs from differentvendors. The architecture provides an abstract service class 500 thatimplements different abstract service types, a workFlowService class 502and another service class type 504. The general abstract service class500 provides methods and objects that all services, e.g., workflowengine vendors, search engine vendors, database program vendors, etc.,must implement to make their services available to users, such as clientand application programs, of the client/server architecture describedherein. The abstract service type class 502 and 504 provides methods andobjects that all services of a particular type must implement such asthe methods and objects that all workflows must implement, all searchengines must implement, etc. The WorkFlowService server 506 and client508 side classes provide the methods and objects for one vendorimplementation of a workflow service and OtherService client 510 andserver 512 classes provide the methods and objects for one particularimplementation of another type of service, e.g., a search engine, etc.

In FIG. 6, a line connecting two classes 500, 502, 504, 506, 508, 510,512 represents an association between the two classes connected by theline, the triangle arrow on one end of the line indicates that the classat the other end of the line inherits the attributes of the classpointed to by the arrow. Thus, abstract workFlowService class 502inherits the attributes of the abstract service class 500 and theWorkFlowService classes 506 and 508 inherit the attributes of theabstract workFlowService class 502, which would include the parentservice class 500.

FIG. 7 illustrates further details of an implementation of theclient/server architecture for enabling access to different servicesfrom different vendors using the class architecture described withrespect to FIG. 6. A plurality of workflow clients 550 a, b, c compriseclient computers, such as workstations, laptops, or any other computingdevice known in the art. Each workflow client 550 a, b, c would includean instance of a workflow service object 552 a, b, c (only 552 a inclient 550 a is shown) instantiated from the WorkFlowService (clientside) class 506. Each workflow client 550 a, b, c includes acommunication protocol 554 a, b, c (only communication protocol 554 a inclient 550 a is shown) that enables communication between the workflowclient 550 a, b, c and a workflow server 556. The communication protocol554 a, b, c comprises a network communication protocol known in the art,such as the Remote Method Invocation (RMI), CORBA, DCOM, etc., is usedto enable communication between methods and objects in theWorkFlowService client 556 to the server side 558. The workflow clients550 a, b, c would communicate with the workflow server 556 over anetwork 564.

The clients 550 a, b, c further include a translator to execute methodsin the WorkFlowService (client side) 506 class. For instance, if theWorkFlowService (client side) 506 class is implemented in an objectoriented language, such as Java**, then the client 550 a, b, c wouldinclude a translator, such as a Java Virtual Machine (JVM), to translatethe method statements to executable code. **MQSeries, IBM, and DB2 areregistered trademarks of International Business Machines Corp., Java isa trademark of Sun Microsystems, Inc.

The workflow server 556 includes a workflow service object (server side)558 that maintains information on a particular vendor implementation ofa workflow engine 560. The workflow server 556 may comprise one or moreserver systems, workstations, or any other computing device known in theart. The workflow service object (server side) 558 is instantiated usingclasses and methods from the WorkFlowService (server side) class 508 forthe particular workflow engine 560. In certain implementations, a useror workflow application 562 could execute methods from theWorkFlowService (client side) 506 class at the workflow client 550 a, b,c to access information from the workflow service object (client side)552 or from the workflow engine 560. In response, such methods would becommunicated via the communication protocol 554 a, b, c to the workflowserver 556 for execution as methods in the WorkFlowService (server side)class 508. Such client methods may be executed against the workflowservice object 558 for information maintained in the workflow serviceobject 558, such as information on the type or category of the workflowengine 560 and a connection, or executed against the workflow engine560.

In the described implementations, the WorkFlowService (client side) 506and WorkFlowService (server side) 508 implement the same methods, withthe exception that methods called on the client side are transferred viathe communication protocol 554 a, b, c, 574 a, b, c to the server 556,576 for execution thereon.

Methods invoked on the workflow server 556 from the WorkFlowServiceobject (server side 558) are translated by a program interface 564 tothe native code used by the workflow engine 560. The program interface564 for translating methods from the WorkFlowService (server side) class508 to native code may comprise a Java Native Interface (JNI), or anyother program known in the art for providing a translation from onelanguage to native code used by the target program or service.

Alternatively, method calls may be initially made on the workflow server556, thereby avoiding the need for communication through thecommunication protocol 554.

A workflow application 562 is written in a computer language, such as anobject oriented language, e.g., Java, C++, etc., and includes code toimplement a workflow using methods and objects from the WorkFlowServiceclasses 506, 508.

In the described implementations, each workflow vendor wanting to maketheir workflow engine 560 product available to users of the architecturewould have to develop methods and classes implementing an instance ofthe WorkFlowService (client side) 506 and (server side) 508 classes,which implement the abstract workFlowService class 502, including atleast the methods and objects of the abstract workFlowService 502 andservice 500 classes. In certain implementations, the vendors wouldutilize the same programming language to provide their WorkFlowService550 a, b, c implementation to users of the architecture, such as theJava programming language**. The program interface 564 would thentranslate the vendor implementation of the WorkFlowService 550 a, b, cto the native code of their workflow service 556.

Similarly, other service clients 570 a, b, c comprise computersincluding an other service object (client side) 572 a, b, c instantiatedfrom the OtherService (client side) class 510. Calls at the client sidewould be communicated via a communication protocol 574 to one otherservice server 576, including an other service object (server side) 578instantiated from the OtherService (server side) class 512. An interface580 translates the methods from the OtherService (server side) class 510to the native code of the other service engine 582, such as a searchengine or any other server-type application program known in the art. Another service application 584 includes methods from the OtherService(client side) 510 or (server side) 512 classes to obtain informationfrom the other service objects (client side) 572 or (server side) 578)or the other service engine 582 in the same manner described withrespect to the workflow service implementation.

Moreover, one client may utilize the methods from multiple client sideservice classes, e.g., from the WorkFlowService (client side) class 506and the OtherService (client side) class 510 to access both serviceengines, e.g., one workflow service engine and one search engine, from asame client. Still further one application program may include methodsto access different services.

Thus, the abstract classes 500, 502, and 504 provide the methods andobjects that any service participating in the heterogeneous serviceenvironment must implement.

The service objects (client side) 558 and 578 include information aboutone connection and the service, e.g., workflow engine 560 or otherservice engine 582. In certain implementations, one workflow serviceobject (client side 552 and server side 558) or other service object(client side 572 or server side 578) is maintained for each active andauthenticated connection to the workflow engine 560 and other serviceengine 582.

In certain implementations, all of the programs and objects shown inFIG. 7 are implemented in a distributed computing system includingnumerous connected computing machines.

Following are examples of some methods and objects in the abstractservice class 500, including:

-   -   connect( ): this method takes as parameters a service name, user        name, authentication, and an optional connection string. The        method authenticates the user having the user name and        authentication with the named service. If the user        authenticates, then connection information is generated and the        handle is returned that addresses the authentication information        for the user. The connection information would be stored in one        service object 558, 578. The user would use the handle to the        connection information when requesting information from the        engine 560, 582. The targeted engine 560, 582 would then use the        handle to verify the user's authentication information to        determine if the user is authorized access to the requested        resource provided by the engine 560, 582. The handle may        subsequently be used to allow the user to access authentication        information without having to go through the authentication        process each time the user requests resources from the engine        560, 582.    -   disconnect( ): voids the authentication so that the handle that        was provided no longer enables access to the engine 560, 582.    -   serviceName( ): returns the name of a service at the engine 560,        582.    -   serviceType( ): returns information on a type of engine 560,        582, e.g., workflow, search engine, etc., by the vendor        providing the service.    -   serviceCategory( ): returns information distinguishing the        category of a engine 560, 582, e.g., workflow, search engines,        etc.    -   userName( ): returns the user name associated with a connection        handle.    -   isConnected( ): returns a boolean value indicating the        connection status for a connection handle.

Following are examples of some methods and objects in the abstractworkFlowService 502, including:

-   -   getDatastore( ): returns a reference to a data store 554        associated with a service defined for the engine 560, 582.    -   listWorkFlows( ): returns a list of workflow objects, such as        workflow objects created using the WorkFlow class 406 methods        discussed above with respect to FIG. 3.    -   listWorkTemplates( ): returns a list of workflow template        objects, such as workflow template objects created using the        WorkFlowTemplate method discussed above as part of the        WorkFlowService class 402.    -   listWorkLists( ): returns a list of work list objects, such as        work list objects created using the WorkList class 408 discussed        above with respect to FIG. 3.

The vendor implemented WorkFlowService classes 506 and 508 includes themethods and objects discussed with respect to the WorkFlowService class402 discussed above and also includes the methods and objects discussedabove with respect to the abstract service 500 and workFlowServiceclasses 502. Similarly the vendor implemented OtherService 510, 512classes would implement the abstract class 500 as well as methods andobjects needed to enable access to information in the service objectsproviding information on one engine 560, 582 c. For instance, theOtherService 510, 512 classes would include methods to connect to theother service and access the resources of the engines 560, 582.

Following are examples of some methods and objects in the implementationof the WorkFlowService classes 506 and 508, including:

-   -   WorkFlowService( ): constructs a workflow service object 552 a,        b, c, 558. Each workflow service object includes information on        groupings of resources available at one workflow engine 560,        e.g., a name of the service, category, type, connection        information, etc.    -   connect( ): constructs a connection handle object including the        authentication information a user needs to connect to one        service engine 560, 582. A connection object would be stored        within one of the workflow service objects (server side) 558.

FIG. 8 illustrates details of the information maintained within theworkflow service object (server side) 558, including a workflow name600, workflow type 602, workflow category 604, and a connection object608. Information in the workflow service object (server side ) 558 isaccessed using the methods of the WorkFlowService (client side) 506 and(server side) 508 classes. As discussed, in certain implementations, theworkflow service object (client side 552 a, b, c) does not includespecific information, and instead comprises a proxy object for methodcalls from the WorkFlowService (client side) 506 class that arecommunicated to the workflow server 556 and implemented through theWorkFlowService (server side) 508 class against the workflow serviceobject (server side) 558. There would be a separate instance of aworkflow service object (client side and server side) for eachconnection to the workflow engine 560, such that each workflow serviceobject maintains information on only one connection. In alternativeimplementations, one service object may maintain multiple connectionobjects for different connections.

FIGS. 9, 10, and 11 illustrate logic implemented in the methods of theservice classes (client side) 506, 510 and (server side) 508, 512. Incertain implementations, the service classes are implemented in anobject oriented programming language, such as Java, C++, etc., and theclients 550 a, b, c, 570 a, b, c and servers 556 and 576 would includeplatforms capable of executing the methods of the service classes. Forinstance, if the service classes are implemented in Java, then theclients 550 a, b, c, 570 a, b, c and servers 556, 576 would include JavaVirtual Machine (JVM) code to execute the methods of the serviceclasses.

FIG. 9 illustrates logic implemented in the WorkFlowService( ) andOtherService( ) methods to instantiate a service object in the serviceclasses (client side) 506, 510 and (server side) 508, 512 to instantiateclient side 552 a, b, c, 572 a, b, c and/or server side 558, 578 serviceobjects, respectively. Control begins at block 650 where a method callis received to construct a service object. If (at block 652) the methodcall is at the client 550 a, b, c, 570 a, b, c, then the method callcauses the clients 550 a, b, c, 570 a, b, c, to construct (at block 654)a client side service object 552 a, b, c, 572 a, b, c and communicate(at block 656) the method to the workflow server 556. If the method callwas invoked at the server 556 (from the no branch of block 652) or fromblock 656, then the method call would cause the server 556, 576 toinstantiate (at block 658) a server side service object 558, 578 andload (at block 660) the instantiated service object into memory. Oncethe service object is instantiated, the client applications 562, 584 canthen issue method calls to access information from the engines 560, 582using the instantiated service object.

FIG. 10 illustrates logic implemented in the connect( ) method toinstantiate a service object in the service classes (client side) 506,510 and (server side) 508, 512 to construct connection object 608 (FIG.8). Control begins at block 670 upon receiving a call to construct aconnection object, including as parameters, a user name, service name,and user authentication information. If (at block 672) the call isclient side, i.e., at the clients 550 a, b, c, 570 a, b, c, then theconnect( ) method is passed to the server 556, 576 via the communicationprotocol 554 a, b, c, 574 a, b, c. From the no branch of block 672 orfrom block 674, the server 556, 576 executes (at block 676) the connect() method and calls the interface 564, 580 to transform the method to thenative code of the engine 560, 582. The engine 560, 582 then attemptsauthentication (at block 678) for the user requesting access to theengine 560, 582 resources. If (at block 680) the user access attempt didnot authenticate, then the engine 560, 582 returns (at block 682) afailure message. Otherwise, if authentication succeeded, then the engine560, 582 instantiates (at block 684) a connection object 608 (FIG. 8)including authentication information for the requested service and username. The connection object 608 is then stored (at block 686) in theservice object 552 a, b, c, 572 a, b, c, and a connection handleaddressing the connection object is returned to the caller to use insubsequent accesses of the engine 560, 572.

FIG. 11 illustrates logic implemented in the methods to accessinformation on an engine in the service classes (client side) 506, 510and (server side) 508, 512. Control begins at block 700 upon receiving acall to a method to obtain information for a named service, including aconnection handle. For instance, the method may request the name of theservice, type, category or resources at the engine 560, 582, e.g., worklists, workflow templates, workflows, etc. If (at block 702) the methodis invoked on the client 550 a, b, c, 570 a, b, c, then the method istransmitted (at block 702) to the server 556, 576. If (at block 706) themethod is requesting information maintained in the service object 558,578, e.g., the category, type, connection, etc., then the information isaccessed (at block 708) from the service object 558, 578 and returned tothe caller. Otherwise, if the requested information is not maintained inthe service object 558, 578, then the interface 564, 580 is called (atblock 710) to transform the method into the native engine 560, 582 code.The engine 560, 582 uses the handle (at block 712) to access theconnection object from the named service 558, 578 to authenticate theuser requesting the information. If (at block 714) the informationprovided in the connection object addressed by the connection handle didnot provide an active and authenticated connection, then a failuremessage is returned (at block 716). Otherwise, if the connection isauthenticated, then the engine 560, 582 executes (at block 718) themethod in the transformed native code, accesses the requestedinformation, e.g., name of workflows, work lists, workflow templates,etc., and returns the requested information to the calling method.

With the described implementations, the service objects 558, 578maintain information on one engine 560, 582 for different connections.Application 562 and 584 and users would utilize methods from the serviceclasses 506, 508, 510, and 512 to access information on engine 560, 582resources from the service objects 558, 578 or the engines 560, 582using the connection object 608 information in the service objects 558,578. The methods to access information from the service object may haveoriginated from methods in the client side 506, 510 or server side 508,512 of the class implementations. Further, the service objects 558 and578 provide authentication services and information that the users andapplications 562 and 584 may access using one connection handle. Oncethe applications 562, 584 or users obtain information on resourcesavailable for an engine 560, 582, the user or application may thenaccess the services directly using methods and objects provided by thevendor for the service to access the particular service, such as theobject oriented workflow class architecture described with respect toFIGS. 3, 4, and 5.

In the described implementations, the workflow 562 and other service 584applications would include the methods and objects of the vendorimplementations of the WorkFlowServices

classes 506, 508, 510, 512 to access the engine 560, 582 resources andinformation thereon. The applications 562 and 584 may include methodsand objects from the service implementations from multiple vendors,thereby allowing the applications to access resources from the servicesprovided by different vendors. For instance, an application may includemethods and objects to perform a search across data stores implementingdata repositories from different vendors, wherein each vendor provides aservice class implementation to enable access to the data repository.This allows for searches, data mining operations, and workflows toaccess data across multiple, heterogeneous content servers. In this way,developers may create applications 562 and 584 that are capable ofaccessing the services provided by different vendors. Moreover, oneapplication may include methods to access different types of resources,such as methods to access workflow resources from one vendor and methodsto access the resources of another service. Still further, oneapplication may include methods and objects from different vendors toaccess the resources of one type of service as provided by differentvendors.

The abstract classes 500, 502, and 504 provide base level methods andobjects that must be included in all vendor implementations of theservice class to provide a standard methodology as to how resources areaccessed and how information on the service is provided in the serviceobjects 558, 578. As discussed above, the abstract classes providemethods and objects concerning how to connect to an engine 560, 582,such as the connect( ) and disconnect( ) methods, and how to obtaininformation on available engine 560, 582 resources, such as theserviceType( ), serviceName( ), servicecategory( ) methods, which applyto all types of services. The abstract workFlowService class 502includes methods and objects to obtain information on the resources ofthe workflow services, such as the getDataStore( ), listWorkLists( ),listWorkFlows( ), and listWorkFlowTemplates( ). By requiring allparticipating vendors to implement the same abstract service classes,the code for different vendors utilize the same methods and objects toprovide access to the resources and information.

Gathering and Distributing Service Information

In the above described implementations, the applications 562, 584 orusers may request information on available engine 560, 582 resourcesthrough various method calls in a service class implementation, such aslistWorkflows, listWorkLists, and listWorkFlowtemplates to obtaininformation on workflows, work lists, and workflow templates. Furtherimplementations provide techniques for delivering up-to-date informationon resources available at the engines 560, 582 to application programs562, 584 and users requesting such information using the methods of theservice class implementations 506, 508, 510, 512.

In certain implementations, a collection object class is provided totransport information from the engines 560, 582 to a calling entity,such as a calling application 562, 584 or user on the client or serversides. The collection object class includes a collection object thatmaintains metadata on different resources in the engine 560, 582. Forinstance, the collection object may be used to maintain information onwork lists, workflows, work templates, etc., in the workflow engine 560,582. Each vendor wanting to make their engine 560, 582 available tousers and applications 562, 584 in the federated system would implementthe collection object class on both the server side and client side. Forinstance, the collection object class may be part of the service classimplementations 506, 508, 510, 512 for each engine 560, 582. Thus, thecollection object class may comprise an abstract class implemented byall vendors whose engine products are to be included in the system.

The collection object class may include the following methods used tomanage collection objects.

-   -   Add: inserts metadata for a resource object, e.g., workflow,        work list, work template, etc., in the engine 560, 582 into a        collection object.    -   Delete: removes metadata for a resource object from the        collection object.    -   Update: updates a workflow object.    -   Retrieve: retrieves the actual resource represented as metadata        in the collection object.    -   Create an iterator: creates an index into the collection object        referencing one metadata element in the collection object.    -   Move Iterator Next: moves the iterator to a next metadata        element in the collection object.    -   Move Iterator Previous: moves the iterator to a previous        metadata element in the collection object.    -   Set Iterator: sets the iterator to a specific metadata element        in the collection object.

FIG. 12 illustrates an example of a collection object 750 includingmetadata elements 752 a, b, c, d on workflow objects available at theworkflow engine 560. The metadata may include the name of the workflowobject and additional brief descriptive information. The collectionobject 750 can be instantiated in response to a call to the methodlistWorkFlows that returns metadata on all workflows at a particularworkflow engine 560,the method listWorkFlowTempates that returnsmetadata on all workflow templates at one workflow engine 560, and tothe method listWorkLists that returns metadata for each work listavailable at one workflow engine 560. Similarly, a collection object maybe constructed to maintain metadata for resources at the other serviceengine 582, such as a content server, and include metadata on queries,searchable resources, etc.

FIGS. 13 and 14 illustrate logic to implement the methods in theWorkFlowService 506, 508 and OtherService 510, 512 classes. FIG. 13illustrates logic implemented in methods to access lists of resources inthe service classes 506, 508, 510, and 512, such as the listWorkFlows,listWorkLists, listWorkFlowTemplates, etc. Control begins at block 800when the server 556, 576 receives a method to access a list ofresources. If (at block 802) the call was initiated at a client 550 a,b, c, 570 a, b, c, then the method is passed (at block 804) to theserver 556, 576 to execute. Whether the method is invoked from theserver 556, 576 (the no branch of block 802) or the clients 556 a, b, c,570 a, b, c (from block 804), the server 556, 576 calls (at block 806)the interface 564, 580 to transforms the method to the engine 560, 582native code and transmits the native code to the engine 560, 582. Inresponse, the engine 560, 582 would generate a list describing theinstances of a particular engine resource, e.g., work lists, workflows,workflow templates, etc.

Upon receiving (at block 808) a list of the engine resources 560, 582from the engine 560, 582, the server 556 would instantiate (at block810) a collection object 750. For each resource instance included in thereceived list, the server 556 would add (at block 812) a metadataelement 752 a, b, c, d to the collection object 750 (FIG. 12). The sever556 would utilize the “Add” method in the collection object class toinsert metadata into the collection object 750. Once the collectionobject 750 includes metadata element for each engine resource instanceincluded in the list, the server 556, 576 returns (at block 814) thecollection object 750 to the calling method, which may be local to theserver 556, 576 or at a remote client 550 a, b, c, 570 a, b, c.

FIG. 14 illustrates the logic of blocks 830 to 838 implemented in theapplications 562, 584 or by a user to access data in the receivedcollection object 750. Upon receiving (at block 830) the collectionobject 750, an iterator is created (at bock 832) to point to a firstmetadata element 752 a, b, c, d in the collection object 750. The useror application 562, 584 would then use (at block 834) the move methodsto move the iterator through the collection object 750 to access andreview metadata elements 752 a, b, c, d. One or more metadata elements752 a, b, c, d may then be selected (at block 836) to access. For eachselected metadata element, a retrieve method, from the collection objectclass, is issued (at block 838) to access the actual resource, e.g.,workflow object, work list object, workflow template, etc., representedby the selected metadata element 752 a, b, c, d.

Blocks 850 to 858 illustrate logic implemented in the collection objectclass to allow the server 556, 576 to process a call to the retrievemethod. At block 850, the server 556, 576 receives a retrieve methodfrom the collection object class. The server then determines (at block852) the method in the server side service class 508, 512 that wouldretrieve the requested resource element, e.g., workflow object, worklist, workflow template, etc. and generates (at block 854) engine 560,582 native code to cause the engine 560, 582 to implement the determinedmethod and return the requested resource object. At block 856, theserver 556 receives the returned resource object from the engine 560,582 represented by the requested metadata element and returns theresource object to the calling method, which may be local to the server556, 576 or remote at one of the clients 550 a, b, c, 570 a, b, c.

The described implementations provide a collection object class toprovide information on resources available at an application program,such as the workflow engine 560. The actual resource objects can be verylarge in size, e.g., hundreds of megabytes. The collection object classallows a server to return metadata on available resources at anapplication program to a requesting user or application. The user orapplication may then use the collection object class methods to reviewthe metadata on the resources in the collection object and retrieve oneor more resource objects represented by metadata elements in thecollection object. The resource object would then be retrieved from theengine and returned to the requesting user or application.

The described implementations provide just-in-time retrieval of datafrom an application, such as a workflow engine, on both the server andclient side when the application needs data. Network performance isimproved because only the minimal amount of information needed tosatisfy the current level of request at the application is transferredto the application, such as metadata elements describing resourceobjects in the application, where each resource object may be very largein size. This aspect allows immediate transmittal of information on theresources in the engine. The application may then request the actualresource object represented by the metadata. In this way, unnecessaryretrieval of large resource objects, and transfer of such data betweenthe servers and clients, is avoided because only specifically requestedlarge resource objects that the application needs are retrieved andtransferred over the network. Unneeded copies of resource objects arenot maintained at the client or servers, and left in the engine untilspecifically requested.

Additional Implementation Details

The preferred embodiments may be implemented as a method, apparatus orarticle of manufacture using standard programming and/or engineeringtechniques to produce software or code. The term “article ofmanufacture” as used herein refers to code or logic implemented in acomputer readable medium (e.g., magnetic storage medium (e.g., hard diskdrives, floppy disks, tape, etc.), optical storage (CD-ROMs, opticaldisks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs,ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.).Code in the computer readable medium is accessed and executed by aprocessor. The code in which preferred embodiments are implemented mayfurther be accessible through a transmission media or from a file serverover a network. In such cases, the article of manufacture in which thecode is implemented may comprise a transmission media, such as a networktransmission line, wireless transmission media, signals propagatingthrough space, radio waves, infrared signals, etc. Of course, thoseskilled in the art will recognize that many modifications may be made tothis configuration without departing from the scope of the presentinvention, and that the article of manufacture may comprise anyinformation bearing medium known in the art.

The workflow client and server may be implemented within any vendorworkflow program known in the art.

In the described implementations, the actions were implemented as Javamethods. Alternatively, the actions may be implemented in anyprogramming language known in the art.

In the described implementations, particular icons were used torepresent different information in the workflow, such as work nodes,exit nodes, etc. However, any icon design may be used to represent theworkflow components. Further, additional graphical representations maybe provided for different types of work nodes, e.g., collection worknodes, assign value node, decision point node, etc.

In the described implementations, the class architecture is implementedas an object oriented class architecture. Alternatively, non-objectoriented programming techniques may be used to implement the describedclass architecture.

The services 552 a, b, c, and 572 a, b, c, may each execute in aseparate computer system comprised of one or more computer devices.Additionally, multiple services 552 a, b, c, 572 a, b, c may execute ina same computer system.

The foregoing description of the preferred embodiments of the inventionhas been presented for the purposes of illustration and description. Itis not intended to be exhaustive or to limit the invention to theprecise form disclosed. Many modifications and variations are possiblein light of the above teaching. It is intended that the scope of theinvention be limited not by this detailed description, but rather by theclaims appended hereto. The above specification, examples and dataprovide a complete description of the manufacture and use of thecomposition of the invention. Since many embodiments of the inventioncan be made without departing from the spirit and scope of theinvention, the invention resides in the claims hereinafter appended.

1. A method for enabling access to workflow resource objects in aplurality of workflow engines, comprising: receiving a request, from acalling entity, for workflow resource objects of a specified type in aspecified workflow engine, wherein the specified type of the requestedresource objects comprises at least one of workflow objects, workflowtemplates and work lists defined in the specified workflow engine,wherein the workflow engine is one of a plurality of workflow enginesenabling access to workflow resource objects, and wherein each workflowengine provides one collection object class implementation of methodsfrom a same abstract collection object class used to instantiate andmanipulate a collection object including metadata on workflow resourceobjects available at the workflow engine; generating a request to theworkflow engine for information on available workflow resource objectsof the specified type; in response to receiving the information from theworkflow engine, generating a collection object using methods from thecollection object class for the workflow engine from which theinformation was returned including one metadata element for eachworkflow resource object of the specified type in the workflow engine,and returning the generated collection object to the calling entity. 2.The method of claim 1, wherein the calling entity comprises anapplication program.
 3. The method of claim 1, wherein the callingentity issues the request from a client and wherein the request isreceived on a server including the workflow engine.
 4. The method ofclaim 1, wherein the request for the workflow resource objects from thecalling entity comprises a method that is a member of a workflow serviceclass implementation of the workflow engine, wherein each workflowengine provides one service class implementation of methods and objectsfrom a same abstract service class implementing the operations ofreceiving the request, generating the request to the workflow engine,generating the collection object, and returning the generated collectionobject.
 5. The method of claim 4, wherein the workflow engine and otherservice engines comprise workflow products from different vendors. 6.The method of claim 5, wherein the workflow service classimplementations from different vendors each include methods and objectsfrom a same abstract workflow service class specifying methods andobjects to include in all workflow service class implementations.
 7. Themethod of claim 1, further comprising: receiving a retrieve method inthe collection object class from the calling entity requesting theworkflow resource object represented by one selected metadata element inthe collection object; generating an additional request to the workflowengine for the workflow resource object requested in the retrievemethod; receiving the requested workflow resource object from theworkflow engine; and returning the requested workflow resource object tothe calling entity invoking the retrieve method.
 8. The method of claim7, wherein the calling entity uses methods from the collection objectclass to access the collection object.
 9. The method of claim 8, whereinthe generated additional request to the workflow engine is in a serviceclass implemented by the workflow engine including methods and objectsto access the workflow engine.
 10. The method of claim 1, wherein therequest for the workflow resource object from the calling entity is in aservice class implemented by the workflow engine that includes methodsand objects to access the workflow engine.
 11. A system for enablingaccess to workflow resource objects, comprising: a plurality of workflowengines enabling access to workflow resources, wherein each workflowengine provides one collection object class implementation of methodsfrom a same abstract collection object class used to instantiate andmanipulate a collection object including metadata on resource objectsavailable at the workflow engine; means for receiving a request, from acalling entity, for workflow resource objects of a specified type in aspecified workflow engine, wherein the specified type of the requestedresource objects comprises at least one of workflow objects, workflowtemplates and work lists defined in the specified workflow engine; meansfor generating a request to the specified workflow engine forinformation on available workflow resource objects of the specifiedtype; means for generating a collection object using methods from thecollection object class for the specified workflow engine, wherein thegenerated collection object includes one metadata element for eachresource object of the specified type in the specified workflow enginein response to receiving the information from the specified workflowengine; and means for returning the generated collection object to thecalling entity.
 12. The system of claim 11, wherein the calling entitycomprises an application program.
 13. The system of claim 11, whereinthe calling entity comprises a client and wherein the means forreceiving the request comprises a server including the workflow engine.14. The system of claim 11, wherein the means for requesting theresource objects from the calling entity uses a method that is a memberof a workflow service class implementation of the workflow engine,wherein each workflow engine provides one service class implementationof methods and objects from a same abstract service class implementingthe means for receiving the request, generating the request to theworkflow engine, generating the collection object, and returning thegenerated collection object.
 15. The system of claim 14, wherein theworkflow engine and other service engines comprise workflow productsfrom different vendors.
 16. The system of claim 15, wherein the workflowservice class implementations from different vendors each includemethods and objects from a same abstract workflow service classspecifying methods and objects to include in all workflow service classimplementations.
 17. The system of claim 11, further comprising: meansfor receiving a retrieve method in the collection object class from thecalling entity requesting the resource object represented by oneselected metadata element in the collection object; means for generatingan additional request to the workflow engine for the resource objectrequested in the retrieve method; means for receiving the requestedresource object from the workflow engine; and means for returning therequested resource object to the calling entity invoking the retrievemethod.
 18. The system of claim 17, wherein the calling entity usesmethods from the collection object class to access the collectionobject.
 19. The system of claim 18, wherein the means for generating theadditional request to the workflow engine comprises a method in aservice class implemented by the workflow engine including methods andobjects to access the workflow engine.
 20. The system of claim 11,wherein the means for requesting the resource object from the callingentity uses methods in a service class implemented by the applicationengine that includes methods and objects to access the workflow engine.21. A computer readable medium including code for enabling access toworkflow resource objects in workflow engine by: receiving a request,from a calling entity, for workflow resource objects of a specified typein the workflow engine, wherein the workflow engine is one of aplurality of workflow engines enabling access to workflow resourceobjects, wherein each workflow engine provides one collection objectclass implementation of methods from a same abstract collection objectclass used to instantiate and manipulate a collection object includingmetadata on resource objects available at the workflow engine;generating a request to the workflow engine for information on availableworkflow resource objects of the specified type, wherein the specifiedtype of the requested resource objects comprises at least one ofworkflow objects, workflow templates and work lists defined in theworkflow engine; in response to receiving the information from theworkflow engine, generating a collection object using methods from thecollection object class including one metadata element for each workflowresource object of the specified type in the workflow engine; andreturning the generated collection object to the calling entity.
 22. Thecomputer readable medium of claim 21, wherein the calling entitycomprises an application program.
 23. The computer readable medium ofclaim 21, wherein the calling entity issues the request from a clientand wherein the request is received on a server including the workflowengine.
 24. The computer readable medium of claim 21, wherein therequest for the resource objects from the calling entity comprises amethod that is a member of a workflow service class implementation ofthe workflow engine, wherein each workflow engine provides one serviceclass implementation of methods and objects from a same abstract serviceclass implementing the operations of receiving the request, generatingthe request to the workflow engine, generating the collection object,and returning the generated collection object.
 25. The computer readablemedium of claim 24, wherein the workflow engine and other serviceengines comprise workflow products from different vendors.
 26. Thecomputer readable medium of claim 25, wherein the workflow service classimplementations from different vendors each include methods and objectsfrom a same abstract workflow service class specifying methods andobjects to include in all workflow service class implementations. 27.The computer readable medium of claim 21, further comprising: receivinga retrieve method in the collection object class from the calling entityrequesting the resource object represented by one selected metadataelement in the collection object; generating an additional request tothe workflow engine for the workflow resource object requested in theretrieve method; receiving the requested workflow resource object fromthe workflow engine; and returning the requested workflow resourceobject to the calling entity invoking the retrieve method.
 28. Thecomputer readable medium of claim 27, wherein the calling entity usesmethods from the collection object class to access the collectionobject.
 29. The computer readable medium of claim 28, wherein thegenerated additional request to the workflow engine is in a serviceclass implemented by the workflow engine including methods and objectsto access the workflow engine.
 30. The computer readable medium of claim21, wherein the request for the workflow resource object from thecalling entity is in a service class implemented by the workflow enginethat includes methods and objects to access the workflow engine.